Alternating-current motor.



V. A. FYNN.

ALTERNATING CURRENT MOTOR.

APPLICATION FILED Imus, 1909.

960,881 Patented June 7,1910.

'UNrrED STATES PATEN onn on vaiinnn ALFRED FYNN, or LoNDoN, ENGLAND.

ALTERNATING-CURRENT MOTOR.

Specification of Letters Patent. Patented June 7, 1910,

original application filed December 19, 1906, Serial 1T0. 348,659. Divided and this application filcdlarch To all whom it moi concern:

Be it known that I, VALnnn'ALrnuo l YNN,

a subject of the King of England, residing at London, England, have invented a cor tain new and useful Alternating-Current.

Motor, of which the following is such a full, clear, and exact description as will ,enable any oneskilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings,

ates to alternating current commutator motors of the single'phasc induction-type the induced and commutedwinding of which is closed over brushes and along more than one axis per pole pair.

The objects of this invention are to make it possible to operate such motors from a.

' single-phase supply at any desired constant speed quite independently of the periodicity of the supply and of the number of poles of the motor, to make it possible to rationall vary or adjust this speed, and to improve thelr commutation.

According to this invention, I adjust the speed of a selfexcited alternate current motor of the said type to a practically constant speed differing from the synchronous, or T' vary its speed, by introducing self-induction into the exciting circuit. placing this selfinduction outside the influence of the rotor working current and by varying its magnitude. In this manner the total flux corresponding to the exciting E. M. F. prevailing at any time will divide itself between that part of the rotor winding which does duty as field winding and the selfrinduction inserted in the exciting circuit, thus leaving only a exciting E. M. ll. for the production of :1- torque and a back E. M. F. along the working axis. I improve the commutation of this machine by adjusting the magnitude of the transformer field due to the main inducing Winding and I im )I'OVO its power factor in the manner alrea y disclosed by me in earlier patents, z'l e. by includin in the w'orkin circuit of the rotor an M. F. approxlmately in hase quadrature with that impressed. on te main stator Winding or by in cl udin in the exciting circuit of the rotor an E." hi 1 approximately in phase Serial No. 481,761.

with thatimpressed on the main inducing winding. a

In the accompanying drawings Figures 1 and 2 diagrammatically show one way of carrying this invention into practice. 1 indicates a possible-mechanical arrangement of such a motor whereas Fig. 2 represents the relative position of the various indings .and connections.

embracin two rotors 45, 46 mounted on the same sha t; Stator 43 carries the main in-- ducing winding 55 connected to the supply and r0tor-45.carries two commuted wind- Fig. 6

43 and 44 represent 'two coaxial stators e5 ings 47 and 49 respectively connected to the /o commutators 48 and 50. Whereas winding 47 only embraces rotor 45, winding 49 embraces both rotors. Winding 47 is short-circuited by way of'brushes 51, 52 alongan axis preferably coinciding with that of the main inducing winding 55 on 43,. winding 49 is short-circuited along an axis preferably displaced by 180/11 degrees with respect to that of the main inducin winding 55 on 43. The

letter n stands, or the number of poles 8-0 I of the motor. The exciting E. M. F. is enerated in that part of windin 49 whic is disposed on rotor 45 and w ich revolves within the transformer field due to the main inducin windin 55 01143, this part of 49 is there ore-the eld winding of the motor. The part of 49 disposed on 46 is nothing but a self-induction within the exciting circuit but outside the influence of the main stator inducing winding and therefore also outside the influence of the transformer-field and of the rotor working current. The flux due to the E. M. F. generated in that part of 49 which is disposed on 45 will divide between the two self-inductions included in the ex- K citing circuit according to the relative magpart of the total flux due to the prevailing E u it-ude of these self-inductions. One of these winding 49, rotor 45 and stator 43-, the other is winding 49, rotor 46 and stator 44;

the greater the latter, the smaller will be the me and consists in longitudinally displacing ll'.

The magnitude of the self- 1H5 stator 44 with respect to rotor46 by means 'ofjthe screw 58 operated by the handle 59 and engaging :1. lug 60 attached to stator 44:, thus caus1n the motor speed to rise more or less above the Synchronous; Then this selfinduction is zero the speed is practically equal to the synchronous I claim 1. In analternating current motor, the combination with an inducing member producing a transformer field, of an induced member having an exciting circuit producing a motorfield and a working circuit, said working circuit being closed by way of brushes along an axis approximately coinciding with that of the transformer field, and means for producing self-induction in said exciting circuit only, said means being disposed outside the inductive influence of both the transformer and the motor fields,

2. In an alternating current motor, the

combination with an inducing member producing a transformer field," of aninduced member having an exciting circuit closed by way of brushes and producing a motor field and a workin circuit, said working circuit being closed y Way of brushes along an axis approximately coinciding with, that of the transformer field, andmeans for producing self induction in said exciting circuit.

only, said means being disposed outside the inductive influence of both the'transformer and the motor fields.

3. in an alternating current motor, the combination with an inducing member producmg a transformer field, of an induced member having an exciting circuit producthe transformer and the motor fields, and

means for varying the magnitude of said self nduction. I

In witness whereof I have hereunto set my hand and aliixed-iny seal in the presence of thc two subscribing witnesses.

VALERIE ALFRED FYNN. [.Ls] \Vitnesses:

W. A. ALEXANDER, E. E. ll'UFrMAN. 

